Cell free translation of chicken calcitonin messenger RNA

Abstract
The primary step of calcitonin biosynthesis was studied in a normal organ: chicken ultimobranchial gland, a tissue particularly rich in calcitonin secretory cells. Poly(A)‐rich RNA was extracted and purified from ultimobranchial organs and translated in a reticulocyte lysate in the presence of labelled methionine. Polyacrylamide gel electrophoresis of specific immunoprecipitates revealed a major band of M r 14 500 and a band of M r 13 300. Thus, in chicken the precursor of calcitonin is a M r 14500 polypeptide. The minor component of M r 13 300 could represent limited processing by the reticulocyte lysate.